1. Field of the Invention
This invention relates to a system for controlling the locomotion of a legged walking robot and, more particularly, to a system for controlling the locomotion of a legged walking robot which enables a biped walking robot to walk stably over irregular terrain.
2. Description of the Prior Art
For increasing the walking speed and reducing the energy consumption of a biped walking robot, it is necessary to abandon static locomotion in which the center of gravity of the system is constantly at the bottom of the foot of the supporting leg in favor of dynamic locomotion utilizing inertial momentum. Examples of dynamic locomotion of a biped walking robot giving attention to this point can be found in a magazine titled "Journal of the Robotics Society of Japan", vol. 3, No. 4 (August, 1985).
The techniques discussed in the journal are, however, premised on the assumption of a disturbance-free, flat terrain and are not capable of achieving dynamic locomotion over a terrain that is irregular or stepped.
While walking over rough terrain or climbing a step, a biped walking robot tends to become most unstable during times when it is supported by one leg. Any attempt to secure greater stability solely by adjusting the size of the feet will have the undesired effect of reducing the robot's terrain adaptability and reducing its walking speed. While performance in these respects can be improved by enlarging the foot bottom area, this is not a wise expedient when considered from the point of the increases in weight and ground contact area this leads to.